Input and Output - Java - page 379

Table 10-3. Scanner methods

Returned
type

“has” method “next” meth-

od

Comment

The next complete token from this scanner

String hasNext() next()

The next string that matches the given regular expres-
sion (regex)

String hasNext(Pattern) next(Pattern)

The next token that matches the regex pattern construc-
ted from the specified string

String hasNext(String) next(String)

BigDecimal hasNextBigDecimal() nextBigDecimal() The next token of the input as a BigDecimal

BigInteger hasNextBigInteger() nextBigInteger() The next token of the input as a BigInteger

The next token of the input as a boolean

boolean hasNextBoolean() nextBoolean()

The next token of the input as a byte byte hasNextByte() nextByte()

The next token of the input as a double

double hasNextDouble() nextDouble()

The next token of the input as a float

float hasNextFloat() nextFloat()

The next token of the input as an int int hasNextInt() nextInt()

N/A Reads up to the end-of-line, including the line ending

String nextLine()

The next token of the input as a long

long hasNextLong() nextLong()

The next token of the input as a short short hasNextShort() nextShort()

The Scanner class is constructed with an input source, which can be a File object
( Chapter 11 ) , an InputStream , a String , or Readable ( Readable is an interface that Read-
er and all its subclasses implement).

One way to use the Scanner is based on the Iterator pattern, using while (scan-
ner.hasNext()) to control the iteration. Example 10-5 shows the simple calculator from
Scanning Input with StreamTokenizer rewritten [ 36 ] to use the Scanner class.

Example 10-5. Simple calculator using java.util.Scanner